Device for treatment or evacuation of intervertebral disc

ABSTRACT

A method of positioning an arcuate tool against inner annular walls of the disc that particularly facilitates reaching posterior and postero-lateral portions of the inner annulus of the disc by arthroscopy. An elongated, arcuate and shape memory tool such as a catheter is positioned against the inner annular wall of the disc, and particularly on the posterior and postero-lateral portions of the inner annulus of the disc, which are portions of the disc to be treated. The deformable and arcuate tool retains its predetermined arcuate shape when no pressure or force is applied to the tool.

This application is a continuation of U.S. application Ser. No.13/967,926 filed Aug. 15, 2013, which is a continuation of U.S.application Ser. No. 13/606,559 filed Sep. 7, 2012, now U.S. Pat. No.8,523,820, which is a divisional of U.S. application Ser. No. 13/042,984filed Mar. 8, 2011, now U.S. Pat. No. 8,308,690, which was acontinuation of U.S. application Ser. No. 11/972,815 filed Jan. 11,2008, now U.S. Pat. No. 7,905,863, which was a continuation of U.S.application Ser. No. 11/112,475 filed Apr. 23, 2005, now U.S. Pat. No.7,322,962, which benefit is claimed hereby, and which claimed priorityon the following Provisional applications:

Applicant claims the benefit of U.S. Provisional Application Ser. No.60/564,838 filed Apr. 23, 2004.

Applicant claims the benefit of U.S. Provisional Application Ser. No.60/572,930 filed May 20, 2004.

Applicant claims the benefit of U.S. Provisional Application Ser. No.60/586,627 filed Jul. 9, 2004.

Applicant claims the benefit of U.S. Provisional Application Ser. No.60/588,582 filed Jul. 16, 2004.

Applicant claims the benefit of U.S. Provisional Application Ser. No.60/588,587 filed Jul. 16, 2004.

FIELD OF INVENTION

This invention and method relate to the treatment or evacuation of anintervertebral disc.

BACKGROUND OF THE INVENTION

The intervertebral disc is comprised of an outer annulus fibrosis and aninternal nucleus pulposus. The healthy annulus is comprised of 10-20lamellae forming a concentric ring of collagen and elastic fibers aroundthe nucleus while the healthy nucleus pulposus is ovoid and composed ofa gelatinous mucoprotein within the confines of the annulus fibrosis.

In the healthy normal disc, the annulus is thick and the internal wallis strong and without significant defects. Aging and trauma causemultiple and varied defects of the annulus as well as changes in thenucleus. These defects are a source of pain for many individuals. It iswidely accepted that the defects which actually do cause pain are eitherposterior or postero-lateral. By far, it is most common that symptomaticdefects are posterior and/or unilateral postero-lateral. Symptomaticdefects which are posterior and bilateral postero-lateral certainly doexist but are definitely less common. On the other hand, degenerativechanges with defects along the inner annular wall can be found commonlyin various other segments of the inner annular wall (anteriorally,antero-laterally on either or both sides, and laterally on either orboth sides. These defects are understood to be asymptomatic, butnevertheless are common.

Radiofrequency is used to treat internal intervertebral disc disruption.Forward pressure is applied to circumvent the nucleus adjacent to theinner annular wall, leverage with the forward pressure against theannular wall opposite to the portion attempting to be treated, or drivethrough the annular tissue which is intended to be treated.

The catheter is advanced around the inside of the nucleus pulposusadjacent to the inner annular wall. However, in the spectrum of discsrequiring treatment, ideal discs are infrequently encountered. Theresult is that the tip of the catheter, even with a bent and/or cappedtip gets caught in defects in the wall, making the advancement difficultor impossible. This frequently results in kinking of the catheter (whichthen typically must be removed), lodging into the defect (presumablyworsening the defect), going through the annular wall (obviouslycreating a through and through defect in the annular wall and evenpotentially puncturing or damaging nerve or vascular structures), andultimately making the intended treatment suboptimal or even impossible.Additionally, in such situations there has been further damage caused tothe disc by the catheter. The defects into which the catheter caninadvertently probe can be the defect, or defects, intended to betreated. Alternately, a defect in the anterior, antero-lateral, orlateral wall can equally be entered inadvertently and cause a disruptionof the procedure. Degenerative disc walls commonly contain multiple suchdefects, as well as thinning of the wall, which are all too frequentlypenetrated.

SUMMARY OF THE INVENTION

The invention includes a method of positioning an S-shaped tool againstinner annular walls of the disc, and particularly on the posterior andpostero-lateral portions of the inner annulus of the disc, byarthroscopy. The apparatus used according to one method requires noforward tip pressure on the inner annular wall of a mammalianintervertebral disc. An arcuate and S-shaped tool such as a catheter ispositioned against the inner annular wall of the disc, and particularlyon the posterior and postero-lateral portions of the inner annulus ofthe disc, which are specifically the portions which need to be treated.The arcuate and S-shaped tool retains its predetermined arcuate andS-shape shape when no pressure or force is applied to the tool.

In another embodiment an arcuate and S-shaped device such as a sheath isused to progressively remove material from the interior of the mammalianintervertebral disc. In yet another embodiment, an arcuate and S-shapedtool device such as a sheath and catheter are used to remove the entireintervertebral disc and place supports to maintain a disc space.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a partial lateral view of a portion of a human spine.

FIG. 2 is a sectioned view taken essentially along line 2-2 of FIG. 1.

FIG. 3 is an exploded view showing the introducer needle, non-conductivesheath, stylet and catheter.

FIG. 4 shows the introducer needle with stylet in place and havingpenetrated the annular wall of the disc.

FIG. 5 shows the introducer needle with the stylet removed.

FIG. 6 shows the non-conductive sheath inserted into and through theintroducer needle, with the S-shaped catheter advanced through thesheath.

FIG. 7 shows the S-shaped catheter extended as required through thesheath.

FIG. 8 demonstrates the introducer needle and sheath being retracted toposition the catheter.

FIG. 9 shows the introducer needle and sheath retracted, and thecatheter positioned against the inner annular wall defect.

FIG. 10 demonstrates the device being withdrawn from the disc and theiatrogenically created defect being sealed.

FIG. 11 demonstrates a range of permissive angles of insertion of theintroducer needle relative to the disc.

FIG. 12 demonstrates the introducer needle penetrating the annular wallat a different angle from that shown in FIGS. 4 through 10.

FIG. 13 demonstrates another angle of entry of the introducer needleinto the disc.

FIG. 14 demonstrates a catheter having multiple orifices therein throughwhich materials may be dispensed.

FIG. 15 is a sectioned view of an introducer needle inserted into asheath having ports therein.

FIG. 16 is a sectioned view of an introducer needle having ports throughwhich materials may be inserted into the disc, or from which materialsmay be removed, such as by vacuuming, and also showing a cutter therein.

FIG. 17 demonstrates an introducer needle and stylet penetrating a disc.

FIG. 18 demonstrates the flexible tip bending on contact with the innerannular wall.

FIG. 19 demonstrates a cutter which may be used to remove material fromthe disc.

FIG. 20 demonstrates removal of a path of disc material using a cutterand a lavage/suction.

FIG. 21 demonstrates a progressive step in removing material from thedisc.

FIG. 22A and FIG. 22B demonstrate additional progressive steps inremoving material from the disc.

FIG. 23 demonstrates yet an additional step in removing material fromthe disc.

FIG. 24 is a sectioned view of, an introducer with a trocar presenttherein.

FIG. 25 is a sectioned view of the introducer with a retractor therein.

FIG. 26 is an oblique partial view of a mammalian spine.

FIG. 27 is an oblique partial view of the mammalian spine with aretractor in position.

FIG. 28 is a sectioned view of a sheath.

FIG. 29 is a sectioned view of a sheath and introducer with a cutter,fiber optic source and lavage and suction in place.

FIG. 30 is plan view of a mammalian intervertebral disc showing aportion of the disc evacuated according to the method of the invention.

FIG. 31 shows placement of a support member within the intervertebraldisc.

FIG. 32 shows a progressive step of the disc being evacuated accordingto the method of the invention.

FIG. 33 shows an additional support being positioned within the disc.

FIG. 34 shows an additional progressive step of the disc being evacuatedaccording to the method of the invention.

FIG. 35 shows an additional support being positioned within the disc.

FIG. 36 shows an additional progressive step of the disc being evacuatedaccording to the method of the invention.

FIG. 37 shows an additional progressive step of the disc being evacuatedaccording to the method of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Turning now to the drawing figures, FIG. 1 shows a partial view of amammalian spine, and more particularly, a human spine 2. FIG. 2 is asectioned view taken essentially along line 2-2 of FIG. 1, and shows anannular wall of a disc 4 of a human spine. The inner annular wall isrough, or jagged, due to trauma, aging and/or disease. Treatment of theportion of the disc labeled 6 is indicated due to its condition.Advancement of a catheter into the disc, and around the wall of the discto the area to be treated is difficult, since the tip of the catheter islikely to engage the rough, jagged inner annular wall. The catheter ispreferred to be laid against the portion of the disc intended to betreated, minimizing the course of the catheter within the disc, yetassuring good contact of the catheter with the portion of the disc to betreated. The angle of entry into the disc should be maximized toaccommodate a spectrum of operative conditions and needle placements.The portion of the disc requiring treatment as contemplated in thisembodiment is postero-lateral (one side or both), plus or minus aportion of the posterior wall. The route to the interior of the discmust be straight. For humans, the distance from the outer layer of skinto interior of the disc is approximately 12 to 30 centimeters, dependingupon the size of the individual upon which the process is performed.

FIG. 3 shows the primary elements of the apparatus of the presentinvention. A stylet 8 is inserted into an introducer needle 10. A lumenin the form of a sheath 12 is subsequently inserted into the introducerneedle, and a catheter 14 having a preformed S shape is advanced throughthe sheath. The lumen acts as a guide through which the S-shaped toolsuch as a catheter, is transported. The guide may take other forms thatwill assist transportation of the tool into the disc, such as a track ora wire that the tool engages. In one embodiment, the guide is part ofthe introducer needle, such as a lumen therein. The introducer needle ispreferred to be straight for ease of placement and due to the distancefrom the skin to the interior of the disc. The introducer will generallyhave a length in excess of 10 centimeters.

The stylet and introducer needle form a passage into the disc throughthe posterior wall of the disc on the side opposite that requiringtreatment. The stylet is intended to keep the tissue from accumulatingwithin the advancing introducer needle.

The introducer needle is advanced under fluoroscopic guidance lateral tothe superior articular process. The annulus is punctured and theintroducer needle may be advanced initially approximately one-third toone-half of the distance of the disc, as can be judged by operatorsskilled in performing such procedures.

FIG. 4 shows the introducer needle with stylet in position. The sharppoint of the stylet is driven through the wall of the disc, along withthe introducer needle. The stylet is then removed. FIG. 5.

After the stylet and introducer needle pierce the annular wall of thedisc and access the interior of the disc, the stylet is removed and isreplaced with a lumen, which may be a sheath. A pre-formed, S-shapedcatheter or other tool having memory retention properties is containedwithin the straight sheath. The straight sheath is inserted through theintroducer needle for introduction into the disc. The catheter isstraightened by the pressure from the walls of the sheath, but thecatheter regains its S-shape as it exits the sheath. As shown in thedrawings, the S-shape comprises two separate and distinct arcs.

The sheath locks into place at the external end of the introducerneedle. When locked into place, the catheter sheath will protrude fromthe tip of the introducer needle. The sheath remains well containedwithin the disc nucleus and not in the proximity of the opposing annularwall but may be advanced or retracted as necessary for catheterpositioning.

The sheath is preferred to be made of nonconductive material havingthermal insulative properties sufficient to avoid undesired heating oftissues and structures outside of the disc, even if the heating portionof the catheter comes into close proximity or even contact with thissheath. The sheath may be straight, or slightly curved, and capable ofadvancing through the introducer needle once the stylet is removed. Ithas sufficient rigidity to maintain a portion of the catheter in astraight position while that portion of the catheter is in the sheath.The sheath is capable of externally locking at an upper portion into theintroducer needle at the hub.

The non-conductive catheter sheath ensures that no inadvertent heatingof the introducer needle occurs. Heating may cause significant unwanteddamage to skin, subcutaneous tissue, fat, muscle, and even nerve.

The sheath is inserted into the lumen of the introducer needle, whilethe introducer needle remains in position within the disc as shown inFIG. 5. In FIG. 6, the catheter is advanced through the sheath. As theS-shaped catheter exits the sheath within the interior of the disc, thecatheter, due to memory retention properties, and with no pressureapplied, assumes its S-shape, with two separate and distinct arcs, asshown in FIG. 6. In FIG. 7, the catheter continues to advance andcontacts the lateral inner annular wall of the side on which thepostero-lateral wall is to be treated. Catheter advancement may befluoroscopically monitored.

FIG. 8 demonstrates the introducer needle being retracted from the discas the catheter is advanced. This combination of movements causes thecatheter to move toward the postero-lateral and posterior wall which isthe intended side of treatment. As shown, the introducer needle andsheath are retracted until the catheter is in position against the siteto be treated. Positioning of the sheath and the catheter may bemonitored fluoroscopically.

As shown in FIG. 9, the introducer needle is retracted until thecatheter rests against the lateral posterior wall to be treated. Thelateral posterior wall to be treated is opposite the side of theposterior wall that the introducer needle has penetrated. Heat or radiofrequency can be applied to the disc wall by means of the catheter.Other therapeutic procedures may be applied by use of an appropriatecatheter. The catheter may then be retracted, and the introducer needleis retracted from the disc as shown in FIG. 10. Either the tip of thiscatheter can be differentially heated to seal the needle entry defect,or the S shaped catheter is removed and replaced with a straightcatheter with a heating element at the tip. Heating of the tip as theneedle-sheath-catheter complex is withdrawn seals the entry defect.Alternately, a catheter with a portal at the tip to inject a sealant ofthis entry defect may be used.

For needle positions between the extremes of acute and obtuse, thelength of sheath versus disbursed catheter will determine the positionat which the catheter tip will come into contact with the oppositelateral wall. Recognition of the goal of having the catheter contact themid portion of the lateral wall of the side to be treated, andmonitoring progress under fluoroscopy will facilitate ideal catheterplacement.

The portion of the catheter intended to be within the disc has an Sshape when no material pressure or force is applied to the catheter. Thecatheter may be formed of nitinol, which is sufficiently flexible to beadvanced through a straight lumen or sheath, but will regain thepreformed arcuate or S-shape when present within the interior of thedisc. The catheter should also be sufficiently flexible to conform tothe shape of the disc wall, such as the posterior wall of the innerdisc, when positioned against the wall. FIG. 9.

The S-shaped catheter allows the physician to treat the posterior wall,and particularly the lateral posterior wall, of a defective disc withoutthe necessity of first contacting the anterior wall with the catheter.The device and process prevent the end or tip of the catheter fromcatching or hanging against the rough interior annular wall, which mayhave many crevices that make it difficult to advance the catheter alongthe wall. The S-shaped catheter allows the catheter to be introducedinto the interior of the disc, and then positioned by manipulation ofthe introducer needle and catheter, without subjecting the catheter tobeing snagged by defects in the disc. The S shape facilitates goodcontact of the catheter with the postero-lateral segment of the disceven if the angle of the needle entry is suboptimal. Additionally, the Sshape retards the catheter traversing through any large segment of theinterior of the disc which is typically filled with debris. Thisminimizes “shoveling” of the debris toward the segment of the innerannular wall to be treated. One skilled in the art will recognize thatsince the S-shape of the tool facilitates reaching the lateral wallportions and surfaces of the disc, which are the most difficult portionsto reach, that the tool of this shape will reach remaining portions andsurfaces of the disc.

Catheters may contain heating segments of various lengths. A finalheating element, which is contained in each of these types of catheters,may be present directly at the tip, and is used for the spot sealing onexit from the inner annular wall. An additional embodiment has astraight catheter with a heating element at the tip.

On withdrawal of the catheter, the end or tip of the catheterstraightens as it is exiting the annular wall. Spot heating at thisposition by tip 16 seals the defect that was created by the introducerand catheter.

FIG. 11 demonstrates an acceptable range of angles of needle insertion18 when driving the introducer needle into the disc. The acceptablerange of angles is within about 70 degrees, but is not less than fortyfive degrees. Due to the S shaped configuration of the catheter, aprecise entry of the introducer needle is not required.

As shown in FIG. 12, acceptable results are achieved with the S-shapedcatheter used according to the novel method, even though the angle ofneedle insertion varies from that shown in FIG. 9. Likewise, the angleof needle insertion may be varied as shown in FIG. 13. The introducerneedle may be withdrawn from the position shown in FIG. 13 to theinterior, posterior annular wall, and S-shaped catheter is capable ofbeing positioned against the lateral posterior wall of the disc by themethod stated above.

The catheter may provide heat or radio frequency for the purpose oftreatment of the disc. Other therapeutic applications may be used withthe device and method. Further, a catheter 20 may have multiple orificesfor the purpose of delivering materials such as adhesives, sealants orfillers into the disc. FIG. 14. A substance 22 may be injected throughthe catheter to the affected site to seal chemically, or otherwise, asopposed to thermally, defects including fissures and tears in theannular wall. Pressure manometery or fibro-optical viewing are alsopossible uses of this catheter system.

FIG. 15 shows a second embodiment of the device, wherein the sheath hasports 32, 34 formed therein. The stylet is shown in position in theintroducer needle of this embodiment. The stylet and introducer needleare used to access the interior annulus of the disc and shown in FIG.17.

After entry into the disc, the stylet is withdrawn. The ports of thesheath may be used to insert materials into the disc, or removematerials from the disc. A vacuum may be applied to the ports for thepurpose of removal of material.

FIG. 18 shows a flexible deformable tip of the sheath. Deformation ofthe tip, which may be visualized fluoroscopically, defines hitting theinner annular wall. In one embodiment, 0.5 centimeters is sufficientprotrusion of the sheath, such that it can be observed to bend when itcontacts opposite inner annular wall. The bending of the tip of thesheath defines the limit of the inner annular wall immediately acrossfrom the entrance of the introducer needle complex into the disc. Thelimit of the inner annular wall opposite to the needle insertion may bedefined when fluoroscopically viewed.

As shown in FIG. 16, a rotary cutter 36 is contained within the sheath.The rotary cutter is used to cut away material as the introducer needleis withdrawn. FIG. 20. Alternately, another type of cutter may be used.

When the introducer needle, sheath and cutter complex are in thenucleus, the tip of the flexible sheath is advanced by externalmanipulation such that it protrudes from the introducer needle. Thethreaded probe protrudes from the sheath, such as by 2-3 mm. Therotating threaded probe is activated to rotate within the inner annularwall. The initial “pass” of the rotating threaded probe is accomplishedby withdrawing the introducer needle/sheath/probe linearly back to theposition where the introducer/sheath tip is at the level of the openinginto the inner annular wall as previously defined. The complex is thenadvanced back to its position at the opposite inner annular wall aspreviously defined fluoroscopically. The sheath/probe is kept in itscurrent position while the introducer needle is withdrawn a pre-defineddistance, such as 5 mm in one embodiment. The complex is again withdrawnwith probe rotating. An additional amount of material is removed,similarly to mowing a lawn. If an additional amount of material ispresent between the first and second probe withdrawals, the amount ofinsertional needle withdrawal can be modified to be less than, forexample, 5 mm. In successive fashion, the complex is advanced, theintroducer needle 40 withdrawn, the rotation of the treaded probe isstarted, the sheath/probe, and then the introducer segment, is withdrawnuntil the final sheath/probe withdrawal is accomplished with theintroducer needle tip at the level of the insertional inner annularwall. Since the sheath is S shaped, short lengths of sheath protrudedfrom the needle will be arcuate. Incrementally longer segments ofexposed sheath assume varying degrees of the S shape. This process verythoroughly evacuates the approximately half of the nucleus that isinitially addressed. At this point, the sheath/probe is withdrawn intothe introducer needle. The sheath/probe is rotated substantially 180degrees within the introducer. The process is then repeated in the samefashion on the opposite half of the nucleus. Infusion of a substance,which could be normal saline, via a side portal 32 into the sheath,alternating with suction at portal 34, may be performed at intervals tofacilitate removal of the nuclear contents.

The sheath has a pre-formed S shape, and a memory for the S shape.Accordingly, as the rotary cutter is extended from the introducerneedle, the sheath will continue to curve slightly, which allowsmaterial 42 which is adjacent to the cut taken in FIG. 20 to be removed.FIG. 21. As the rotary cutter cuts material away, lavage/suction areapplied through the ports 34 of the introducer needle. One port allowsfor infusion of a substance (which may be normal saline) into one port.The other port is for suction or other form of removal of materialincluding debris from the disc. By increasing the length of the S shapedsheath from the needle 40, additional passes each take material from thedisc, as the cutter is further extended from the sheath. FIG. 22Ademonstrates the cutter after the cutter has made six passes, and isbeginning a seventh pass. In each pass, the arcuate shape of the sheathas it is extended which allows for progressively removing from theinterior of the disc. Shorter segments of the sheath exposed from theintroducer needle have an arcuate shape allowing for an infinite numberof paths throughout the disc enabling the removal of nuclear material ifneeded.

After the material is removed from one side of the disc, the cutter isretracted into the needle. The cutter and/or the sheath are rotated 180degrees, so that the S shaped cutter is present on the opposite side ofthe disc. FIG. 22B. The sheath containing the cutter is extended fromthe introducer needle on each subsequent pass as needed, until materialis removed as desired from the disc as shown in FIG. 23.

FIG. 24 shows a trocar 50 that is a present within an introducer 52. Thetrocar may be a relatively large stylet. FIG. 25 shows a retractor 54that is present within the introducer. The retractor manipulates thenerve root 56.

FIG. 26 shows a vertebra 58 of a mammalian spine, an additional vertebra60 of a mammalian spine, with an intervertebral disc 62 between thevertebrae. Also shown are a pedicle 64, a superior articular facet 68and an inferior articular facet 66. The nerve root 56 is shown astraversing the intervertebral disc. As shown, the position of the nerveroot interferes with access to the intervertebral disc. FIG. 26 is anoblique view demonstrating what is typically visualized fluoroscopicallyfor intradiscal procedures, except for the nerve root, which does notvisualize under fluoroscopy, but whose position is known to anexperienced operator.

The trocar is used to pierce and penetrate skin and other tissue. Uponreaching the nerve root, the trocar is removed and the retractor isinserted. The retractor is used to lift the nerve root over theintroducer needle, so that the nerve root is out of the way, and doesnot interfere with access to the intervertebral disc. FIG. 27.

Once the retractor has repositioned the nerve root over the introducer,the retractor may be removed from the introducer, and the trocarreinserted into the introducer. With the nerve root positioned over theintroducer, the nerve root will not be damaged as the trocar andintroducer are inserted into the intervertebral disc. The trocar piercesthe intervertebral disc for access to the disc with the introducer.

FIG. 28 demonstrates a cross section of a sheath 70 that is used toevacuate a defective disc according to the method described. The sheathhas three lumens in the embodiment shown. A first lumen 72 is used as aconduit for a fiber optic cable. A second lumen 74 is provided throughwhich a cutter is delivered to the work site within the intervertebraldisc. The cutter could be a laser cutter, or a mechanical cutter, suchas a rotary cutter.

A third lumen 76 is relatively larger, and provides a conduit for lavageand suction. Saline or other materials may be introduced to the worksite in the disc through the lumen. Tissue that is removed, along withattendant blood and other materials, may be suctioned and evacuatedthrough lumen 76.

FIG. 29 shows the fiber optic source 78, cutter 80 and the conduit forlavage and suction 82.

The introducer penetrates the wall of the disc as described above. Theintroducer is shown as having penetrated the lateral posterior wall ofthe disc 84 in FIG. 30. The sheath is positioned within the disc throughthe introducer. The sheath is initially positioned so that its forwardend extends only slightly beyond the end of the introducer needle. Thecutter, the fiber optic and the lavage and suction are actuated, and theentire assembly, along with the introducer needle, are pushed to theopposite wall 86 of the disc, which in this case, is the lateralanterior portion of the disc so that the pulposa of the disc and thedisc wall itself are removed, as shown in FIG. 30. Since the materiallyextended sheath has an S-shape when no pressure is applied to thesheath, there will be a slight curvature of the sheath as it marginallyextends from the introducer needle. Accordingly, the cut as shown inFIG. 30 is somewhat conical in shape, rather than being straight, due tothe arcuate shape of the sheath when the sheath is advanced slightlyfrom the introducer.

The evacuation progresses outwardly. As the intervertebral disc isremoved, support must be provided for the adjoining the vertebrae. FIG.31 shows the cutter removed from the sheath, and a support member orstrut 88 placed in position using insertion or placement tool. Thesupport member or strut may be capable of inflation using, for example,saline. Accordingly, the support member or strut may be a balloon orbladder.

The sheath is progressively extended, and progressive cuts are madeusing the introducer to traverse generally linearly in and out of thedisc. As shown in FIG. 32, progressive cuts are made until the disc andassociated pulposa 90 are substantially completely removed from one sideof the introducer needle. The cutter may be removed from the sheath asrequired, and the placement tool inserted for placement of the supportmembers or struts within the intervertebral disc.

After one side of the disc is substantially removed, the sheath, and/orthe introducer needle and sheath, are rotated 180 degrees. FIG. 34. Thecutter is in position in the sheath. Additional progressive passes aremade by steering and advancing the introducer and sheath, individually,or as a unit within the disc, and with the cutter in place. The sheathis progressively extended on each pass, so that the portion of the discthat is further away from the introducer is removed with eachprogressive pass.

The S-shape of the sheath permits the material of the disc to be removedwhich is offset to each side of the introducer, even though theintroducer is advanced and retracted on what is generally a straightline dictated by the void formed in the disc through which theintroducer passes. The S-shape of the sheath allows the cutter to reachprogressively laterally as the sheath is progressively extended from theintroducer. The sheath of this embodiment, and the catheter shown inFIG. 3 through FIG. 14, and the sheath shown in FIG. 22A through FIG.23, each have an S-shape when no material pressure is applied to thecatheter or sheath. The catheter or sheath in each embodiment of theinvention shown herein has a memory property which returns the catheteror sheath to an S-shape when no material pressure is applied to thecatheter or sheath. However, when the catheter or sheath is presentwithin the introducer, or in the case of the catheter, within the sheathfor the catheter, the S shaped element is reformed to be straight, butregains it S shape as it exits the straight lumen. The sheath ispreferred to be straight, and in some embodiments, rigid when used withan S-shaped catheter or tool having shape memory.

Continuing with the process of this preferred embodiment as shown in thedrawings, FIG. 36 demonstrates the final cutting away of the disc byslight protrusion of the sheath from the introducer. FIG. 37 uses thecutter with the cutter even more slightly extending from the needle toremove the disc. However, in practice, it may be necessary to remove theentire intervertebral disc. It may be desirable to leave some of theintervertebral disc in place as a support, as long as the targeteddefective portion of the intervertebral disc is removed by the methoddescribed herein.

The procedures and processes described herein may be, and are preferredto be, performed percutaneously. The procedures and processes may beperformed using stab incision or small incision techniques, ortechniques wherein an incision of about 2.5 centimeters or less is usedto provide access for the introducer, the sheath and/or the tool.

What is claimed is:
 1. A device for treatment or evacuation of aninterior of a mammalian intervertebral disc, comprising: an introducercomprising a guide constructed an arranged for insertion through anopening in a posterior wall of mammalian intervertebral disc; anelongated tool formed of a shape memory material and comprising apreformed arcuate shape, the elongated tool and guide constructed andarranged for advancement of said elongated tool along said guide,wherein said preformed arcuate shape of said elongated tool is deformedby said guide while said preformed arcuate shape of the elongated toolengages said guide, and wherein the elongated tool is constructed andarranged to reassume its preformed arcuate shape upon exiting the guideand while in the interior of the mammalian intervertebral disc, andwherein the preformed arcuate shape of the elongated tool is constructedand arranged for selectively contacting substantially all surfaces of aninterior of the wall of the mammalian intervertebral disc from selectiveadvancement and retraction of the elongated tool within the interior ofthe mammalian intervertebral disc with independent selective advancementand retraction of the introducer.
 2. A device for treatment orevacuation of an interior of a mammalian intervertebral disc asdescribed in claim 1, wherein said guide comprises a lumen, and wheresaid elongated tool slidably engages said lumen as said elongated toolis transported into the interior of the mammalian intervertebral discthrough said lumen.
 3. A device for treatment or evacuation of aninterior of a mammalian intervertebral disc as described in claim 1,wherein said elongated tool comprises a deformable locator tip on adistal end of said elongated tool, wherein said deformable locator tipis visible under a fluoroscope, and wherein said deformable locator tipis constructed and arranged to deform upon contact under pressure withthe interior wall of the mammalian intervertebral disc.
 4. A device fortreatment or evacuation of an interior of a mammalian intervertebraldisc as described in claim 1, wherein said elongated tool is a catheter.5. A device for treatment or evacuation of an interior of a mammalianintervertebral disc as described in claim 1, wherein said guide is asheath.
 6. A device for treatment or evacuation of an interior of amammalian intervertebral disc as described in claim 1, wherein saidelongated tool comprises a cutter.
 7. A device for treatment orevacuation of an interior of a mammalian intervertebral disc asdescribed in claim 1, wherein said elongated tool comprises a device foremitting radio frequency.
 8. A device for treatment or evacuation of aninterior of a mammalian intervertebral disc as described in claim 1,wherein said elongated tool comprises a device for emitting heat.
 9. Adevice for treatment or evacuation of the interior of a mammalianintervertebral disc as described in claim 1, wherein said guide of saidintroducer comprises a substantially straight lumen that forms saidelongated tool as substantially straight as said elongated tool slidablyengages said lumen.
 10. A device for treatment or evacuation of theinterior of a mammalian intervertebral disc as described in claim 1,wherein said elongated tool is rotatable relative to the introducer andthe preformed arcuate shape of the elongated tool is constructed andarranged for positioning on a side of the mammalian intervertebral discthat is opposite a first side of the mammalian intervertebral disc afterrotation of the elongated tool relative to the introducer.